
/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <ngx_http_perl_module.h>


typedef struct
{
    PerlInterpreter *perl;
    HV              *nginx;
    ngx_array_t     *modules;
    ngx_array_t *requires;
} ngx_http_perl_main_conf_t;


typedef struct
{
    SV       *sub;
    ngx_str_t handler;
} ngx_http_perl_loc_conf_t;


typedef struct
{
    SV       *sub;
    ngx_str_t handler;
} ngx_http_perl_variable_t;


#if (NGX_HTTP_SSI)
static ngx_int_t ngx_http_perl_ssi(ngx_http_request_t *r,
                                   ngx_http_ssi_ctx_t *ssi_ctx,
                                   ngx_str_t         **params);
#endif

static char *ngx_http_perl_init_interpreter(ngx_conf_t                *cf,
                                            ngx_http_perl_main_conf_t *pmcf);
static PerlInterpreter                  *
ngx_http_perl_create_interpreter(ngx_conf_t                *cf,
                                                  ngx_http_perl_main_conf_t *pmcf);
static ngx_int_t ngx_http_perl_run_requires(pTHX_ ngx_array_t *requires,
                                            ngx_log_t *log);
static ngx_int_t ngx_http_perl_call_handler(pTHX_ ngx_http_request_t *r,
                                            ngx_http_perl_ctx_t *ctx, HV *nginx,
                                            SV *sub, SV **args,
                                            ngx_str_t *handler, ngx_str_t *rv);
static void      ngx_http_perl_eval_anon_sub(pTHX_ ngx_str_t *handler, SV **sv);

static ngx_int_t ngx_http_perl_preconfiguration(ngx_conf_t *cf);
static void     *ngx_http_perl_create_main_conf(ngx_conf_t *cf);
static char     *ngx_http_perl_init_main_conf(ngx_conf_t *cf, void *conf);
static void     *ngx_http_perl_create_loc_conf(ngx_conf_t *cf);
static char     *ngx_http_perl_merge_loc_conf(ngx_conf_t *cf, void *parent,
                                              void *child);
static char     *ngx_http_perl(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_http_perl_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);

#if (NGX_HAVE_PERL_MULTIPLICITY)
static void ngx_http_perl_cleanup_perl(void *data);
#endif

static ngx_int_t ngx_http_perl_init_worker(ngx_cycle_t *cycle);
static void      ngx_http_perl_exit(ngx_cycle_t *cycle);


static ngx_command_t ngx_http_perl_commands[] = {

    {ngx_string("perl_modules"), NGX_HTTP_MAIN_CONF | NGX_CONF_TAKE1,
     ngx_conf_set_str_array_slot, NGX_HTTP_MAIN_CONF_OFFSET,
     offsetof(ngx_http_perl_main_conf_t, modules), NULL},

    {ngx_string("perl_require"), NGX_HTTP_MAIN_CONF | NGX_CONF_TAKE1,
     ngx_conf_set_str_array_slot, NGX_HTTP_MAIN_CONF_OFFSET,
     offsetof(ngx_http_perl_main_conf_t, requires), NULL},

    {ngx_string("perl"), NGX_HTTP_LOC_CONF | NGX_HTTP_LMT_CONF | NGX_CONF_TAKE1,
     ngx_http_perl, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL},

    {ngx_string("perl_set"), NGX_HTTP_MAIN_CONF | NGX_CONF_TAKE2,
     ngx_http_perl_set, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL},

    ngx_null_command};


static ngx_http_module_t ngx_http_perl_module_ctx = {
    ngx_http_perl_preconfiguration, /* preconfiguration */
    NULL,                           /* postconfiguration */

    ngx_http_perl_create_main_conf, /* create main configuration */
    ngx_http_perl_init_main_conf,   /* init main configuration */

    NULL, /* create server configuration */
    NULL, /* merge server configuration */

    ngx_http_perl_create_loc_conf, /* create location configuration */
    ngx_http_perl_merge_loc_conf   /* merge location configuration */
};


ngx_module_t ngx_http_perl_module = {
    NGX_MODULE_V1,
    &ngx_http_perl_module_ctx, /* module context */
    ngx_http_perl_commands,    /* module directives */
    NGX_HTTP_MODULE,           /* module type */
    NULL,                      /* init master */
    NULL,                      /* init module */
    ngx_http_perl_init_worker, /* init process */
    NULL,                      /* init thread */
    NULL,                      /* exit thread */
    NULL,                      /* exit process */
    ngx_http_perl_exit,        /* exit master */
    NGX_MODULE_V1_PADDING};


#if (NGX_HTTP_SSI)

#define NGX_HTTP_PERL_SSI_SUB 0
#define NGX_HTTP_PERL_SSI_ARG 1


static ngx_http_ssi_param_t ngx_http_perl_ssi_params[] = {
    {ngx_string("sub"), NGX_HTTP_PERL_SSI_SUB, 1, 0},
    {ngx_string("arg"), NGX_HTTP_PERL_SSI_ARG, 0, 1},
    {ngx_null_string, 0, 0, 0}};

static ngx_http_ssi_command_t ngx_http_perl_ssi_command = {
    ngx_string("perl"), ngx_http_perl_ssi, ngx_http_perl_ssi_params, 0, 0, 1};

#endif


static ngx_str_t ngx_null_name = ngx_null_string;
static HV       *nginx_stash;

#if (NGX_HAVE_PERL_MULTIPLICITY)
static ngx_uint_t ngx_perl_term;
#else
static PerlInterpreter *perl;
#endif


static void
ngx_http_perl_xs_init(pTHX)
{
    newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, __FILE__);

    nginx_stash = gv_stashpv("nginx", TRUE);
}


static ngx_int_t
ngx_http_perl_handler(ngx_http_request_t *r)
{
    r->main->count++;

    ngx_http_perl_handle_request(r);

    return NGX_DONE;
}


void
ngx_http_perl_handle_request(ngx_http_request_t *r)
{
    SV                        *sub;
    ngx_int_t                  rc;
    ngx_str_t                  uri, args, *handler;
    ngx_uint_t                 flags;
    ngx_http_perl_ctx_t       *ctx;
    ngx_http_perl_loc_conf_t  *plcf;
    ngx_http_perl_main_conf_t *pmcf;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "perl handler");

    ctx = ngx_http_get_module_ctx(r, ngx_http_perl_module);

    if (ctx == NULL)
    {
        ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_perl_ctx_t));
        if (ctx == NULL)
        {
            ngx_http_finalize_request(r, NGX_ERROR);
            return;
        }

        ngx_http_set_ctx(r, ctx, ngx_http_perl_module);

        ctx->request = r;
    }

    pmcf = ngx_http_get_module_main_conf(r, ngx_http_perl_module);

    {
        dTHXa(pmcf->perl);
        PERL_SET_CONTEXT(pmcf->perl);
        PERL_SET_INTERP(pmcf->perl);

        if (ctx->next == NULL)
        {
            plcf    = ngx_http_get_module_loc_conf(r, ngx_http_perl_module);
            sub     = plcf->sub;
            handler = &plcf->handler;
        }
        else
        {
            sub       = ctx->next;
            handler   = &ngx_null_name;
            ctx->next = NULL;
        }

        rc = ngx_http_perl_call_handler(aTHX_ r, ctx, pmcf->nginx, sub, NULL,
                                        handler, NULL);
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl handler done: %i", rc);

    if (rc > 600)
    {
        rc = NGX_OK;
    }

    if (ctx->redirect_uri.len)
    {
        uri = ctx->redirect_uri;
    }
    else
    {
        uri.len = 0;
    }

    ctx->filename.data    = NULL;
    ctx->redirect_uri.len = 0;

    if (rc == NGX_ERROR)
    {
        ngx_http_finalize_request(r, rc);
        return;
    }

    if (ctx->done || ctx->next)
    {
        ngx_http_finalize_request(r, NGX_DONE);
        return;
    }

    if (uri.len)
    {
        if (uri.data[0] == '@')
        {
            ngx_http_named_location(r, &uri);
        }
        else
        {
            ngx_str_null(&args);
            flags = NGX_HTTP_LOG_UNSAFE;

            if (ngx_http_parse_unsafe_uri(r, &uri, &args, &flags) != NGX_OK)
            {
                ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }

            ngx_http_internal_redirect(r, &uri, &args);
        }

        ngx_http_finalize_request(r, NGX_DONE);
        return;
    }

    if (rc == NGX_OK || rc == NGX_HTTP_OK)
    {
        ngx_http_send_special(r, NGX_HTTP_LAST);
        ctx->done = 1;
    }

    ngx_http_finalize_request(r, rc);
}


void
ngx_http_perl_sleep_handler(ngx_http_request_t *r)
{
    ngx_event_t *wev;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl sleep handler");

    wev = r->connection->write;

    if (wev->delayed)
    {
        if (ngx_handle_write_event(wev, 0) != NGX_OK)
        {
            ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        }

        return;
    }

    ngx_http_perl_handle_request(r);
}


static ngx_int_t
ngx_http_perl_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v,
                       uintptr_t data)
{
    ngx_http_perl_variable_t *pv = (ngx_http_perl_variable_t *)data;

    ngx_int_t                  rc;
    ngx_str_t                  value;
    ngx_uint_t                 saved;
    ngx_http_perl_ctx_t       *ctx;
    ngx_http_perl_main_conf_t *pmcf;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl variable handler");

    ctx = ngx_http_get_module_ctx(r, ngx_http_perl_module);

    if (ctx == NULL)
    {
        ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_perl_ctx_t));
        if (ctx == NULL)
        {
            return NGX_ERROR;
        }

        ngx_http_set_ctx(r, ctx, ngx_http_perl_module);

        ctx->request = r;
    }

    saved         = ctx->variable;
    ctx->variable = 1;

    pmcf = ngx_http_get_module_main_conf(r, ngx_http_perl_module);

    value.data = NULL;

    {
        dTHXa(pmcf->perl);
        PERL_SET_CONTEXT(pmcf->perl);
        PERL_SET_INTERP(pmcf->perl);

        rc = ngx_http_perl_call_handler(aTHX_ r, ctx, pmcf->nginx, pv->sub,
                                        NULL, &pv->handler, &value);
    }

    if (value.data)
    {
        v->len          = value.len;
        v->valid        = 1;
        v->no_cacheable = 0;
        v->not_found    = 0;
        v->data         = value.data;
    }
    else
    {
        v->not_found = 1;
    }

    ctx->variable         = saved;
    ctx->filename.data    = NULL;
    ctx->redirect_uri.len = 0;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl variable done");

    return rc;
}


#if (NGX_HTTP_SSI)

static ngx_int_t
ngx_http_perl_ssi(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ssi_ctx,
                  ngx_str_t **params)
{
    SV                        *sv, **asv;
    ngx_int_t                  rc;
    ngx_str_t                 *handler, **args;
    ngx_uint_t                 i;
    ngx_http_perl_ctx_t       *ctx;
    ngx_http_perl_main_conf_t *pmcf;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl ssi handler");

    ctx = ngx_http_get_module_ctx(r, ngx_http_perl_module);

    if (ctx == NULL)
    {
        ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_perl_ctx_t));
        if (ctx == NULL)
        {
            return NGX_ERROR;
        }

        ngx_http_set_ctx(r, ctx, ngx_http_perl_module);

        ctx->request = r;
    }

    pmcf = ngx_http_get_module_main_conf(r, ngx_http_perl_module);

    ctx->ssi         = ssi_ctx;
    ctx->header_sent = 1;

    handler                     = params[NGX_HTTP_PERL_SSI_SUB];
    handler->data[handler->len] = '\0';

    {
        dTHXa(pmcf->perl);
        PERL_SET_CONTEXT(pmcf->perl);
        PERL_SET_INTERP(pmcf->perl);

#if 0

    /* the code is disabled to force the precompiled perl code using only */

    ngx_http_perl_eval_anon_sub(aTHX_ handler, &sv);

    if (sv == &PL_sv_undef) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "eval_pv(\"%V\") failed", handler);
        return NGX_ERROR;
    }

    if (sv == NULL) {
        sv = newSVpvn((char *) handler->data, handler->len);
    }

#endif

        sv = newSVpvn((char *)handler->data, handler->len);

        args = &params[NGX_HTTP_PERL_SSI_ARG];

        if (args[0])
        {
            for (i = 0; args[i]; i++)
            { /* void */
            }

            asv = ngx_pcalloc(r->pool, (i + 1) * sizeof(SV *));

            if (asv == NULL)
            {
                SvREFCNT_dec(sv);
                return NGX_ERROR;
            }

            asv[0] = (SV *)(uintptr_t)i;

            for (i = 0; args[i]; i++)
            {
                asv[i + 1] = newSVpvn((char *)args[i]->data, args[i]->len);
            }
        }
        else
        {
            asv = NULL;
        }

        rc = ngx_http_perl_call_handler(aTHX_ r, ctx, pmcf->nginx, sv, asv,
                                        handler, NULL);

        SvREFCNT_dec(sv);
    }

    ctx->filename.data    = NULL;
    ctx->redirect_uri.len = 0;
    ctx->ssi              = NULL;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "perl ssi done");

    return rc;
}

#endif


static char *
ngx_http_perl_init_interpreter(ngx_conf_t *cf, ngx_http_perl_main_conf_t *pmcf)
{
    ngx_str_t *m;
    ngx_uint_t i;
#if (NGX_HAVE_PERL_MULTIPLICITY)
    ngx_pool_cleanup_t *cln;

    cln = ngx_pool_cleanup_add(cf->pool, 0);
    if (cln == NULL)
    {
        return NGX_CONF_ERROR;
    }

#endif

#ifdef NGX_PERL_MODULES
    if (pmcf->modules == NGX_CONF_UNSET_PTR)
    {
        pmcf->modules = ngx_array_create(cf->pool, 1, sizeof(ngx_str_t));
        if (pmcf->modules == NULL)
        {
            return NGX_CONF_ERROR;
        }

        m = ngx_array_push(pmcf->modules);
        if (m == NULL)
        {
            return NGX_CONF_ERROR;
        }

        ngx_str_set(m, NGX_PERL_MODULES);
    }
#endif

    if (pmcf->modules != NGX_CONF_UNSET_PTR)
    {
        m = pmcf->modules->elts;
        for (i = 0; i < pmcf->modules->nelts; i++)
        {
            if (ngx_conf_full_name(cf->cycle, &m[i], 0) != NGX_OK)
            {
                return NGX_CONF_ERROR;
            }
        }
    }

#if !(NGX_HAVE_PERL_MULTIPLICITY)

    if (perl)
    {
        if (ngx_set_environment(cf->cycle, NULL) == NULL)
        {
            return NGX_CONF_ERROR;
        }

        if (ngx_http_perl_run_requires(aTHX_ pmcf->requires, cf->log) != NGX_OK)
        {
            return NGX_CONF_ERROR;
        }

        pmcf->perl  = perl;
        pmcf->nginx = nginx_stash;

        return NGX_CONF_OK;
    }

#endif

    if (nginx_stash == NULL)
    {
        PERL_SYS_INIT(&ngx_argc, &ngx_argv);
    }

    pmcf->perl = ngx_http_perl_create_interpreter(cf, pmcf);

    if (pmcf->perl == NULL)
    {
        return NGX_CONF_ERROR;
    }

    pmcf->nginx = nginx_stash;

#if (NGX_HAVE_PERL_MULTIPLICITY)

    cln->handler = ngx_http_perl_cleanup_perl;
    cln->data    = pmcf->perl;

#else

    perl = pmcf->perl;

#endif

    return NGX_CONF_OK;
}


static PerlInterpreter *
ngx_http_perl_create_interpreter(ngx_conf_t                *cf,
                                 ngx_http_perl_main_conf_t *pmcf)
{
    int              n;
    STRLEN           len;
    SV              *sv;
    char            *ver, **embedding;
    ngx_str_t       *m;
    ngx_uint_t       i;
    PerlInterpreter *perl;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, cf->log, 0, "create perl interpreter");

    if (ngx_set_environment(cf->cycle, NULL) == NULL)
    {
        return NULL;
    }

    perl = perl_alloc();
    if (perl == NULL)
    {
        ngx_log_error(NGX_LOG_ALERT, cf->log, 0, "perl_alloc() failed");
        return NULL;
    }

    {
        dTHXa(perl);
        PERL_SET_CONTEXT(perl);
        PERL_SET_INTERP(perl);

        perl_construct(perl);

#ifdef PERL_EXIT_DESTRUCT_END
        PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
#endif

        n = (pmcf->modules != NGX_CONF_UNSET_PTR) ? pmcf->modules->nelts * 2
                                                  : 0;

        embedding = ngx_palloc(cf->pool, (5 + n) * sizeof(char *));
        if (embedding == NULL)
        {
            goto fail;
        }

        embedding[0] = "";

        if (n++)
        {
            m = pmcf->modules->elts;
            for (i = 0; i < pmcf->modules->nelts; i++)
            {
                embedding[2 * i + 1] = "-I";
                embedding[2 * i + 2] = (char *)m[i].data;
            }
        }

        embedding[n++] = "-Mnginx";
        embedding[n++] = "-e";
        embedding[n++] = "0";
        embedding[n]   = NULL;

        n = perl_parse(perl, ngx_http_perl_xs_init, n, embedding, NULL);

        if (n != 0)
        {
            ngx_log_error(NGX_LOG_ALERT, cf->log, 0, "perl_parse() failed: %d",
                          n);
            goto fail;
        }

        sv  = get_sv("nginx::VERSION", FALSE);
        ver = SvPV(sv, len);

        if (ngx_strcmp(ver, NGINX_VERSION) != 0)
        {
            ngx_log_error(NGX_LOG_ALERT, cf->log, 0,
                          "version " NGINX_VERSION " of nginx.pm is required, "
                          "but %s was found",
                          ver);
            goto fail;
        }

        if (ngx_http_perl_run_requires(aTHX_ pmcf->requires, cf->log) != NGX_OK)
        {
            goto fail;
        }
    }

    return perl;

fail:

    (void)perl_destruct(perl);

    perl_free(perl);

    return NULL;
}


static ngx_int_t
ngx_http_perl_run_requires(pTHX_ ngx_array_t *requires, ngx_log_t *log)
{
    u_char    *err;
    STRLEN     len;
    ngx_str_t *script;
    ngx_uint_t i;

    if (requires == NGX_CONF_UNSET_PTR)
    {
        return NGX_OK;
    }

    script = requires->elts;
    for (i = 0; i < requires->nelts; i++)
    {
        require_pv((char *)script[i].data);

        if (SvTRUE(ERRSV))
        {
            err = (u_char *)SvPV(ERRSV, len);
            while (--len && (err[len] == CR || err[len] == LF))
            { /* void */
            }

            ngx_log_error(NGX_LOG_EMERG, log, 0,
                          "require_pv(\"%s\") failed: \"%*s\"", script[i].data,
                          len + 1, err);

            return NGX_ERROR;
        }
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_perl_call_handler(pTHX_ ngx_http_request_t *r,
                           ngx_http_perl_ctx_t *ctx, HV *nginx, SV *sub,
                           SV **args, ngx_str_t *handler, ngx_str_t *rv)
{
    SV               *sv;
    int               n, status;
    char             *line;
    u_char           *err;
    STRLEN            len, n_a;
    ngx_uint_t        i;
    ngx_connection_t *c;

    dSP;

    status = 0;

    ctx->error  = 0;
    ctx->status = NGX_OK;

    ENTER;
    SAVETMPS;

    PUSHMARK(sp);

    sv = sv_2mortal(sv_bless(newRV_noinc(newSViv(PTR2IV(ctx))), nginx));
    XPUSHs(sv);

    if (args)
    {
        EXTEND(sp, (intptr_t)args[0]);

        for (i = 1; i <= (uintptr_t)args[0]; i++)
        {
            PUSHs(sv_2mortal(args[i]));
        }
    }

    PUTBACK;

    c = r->connection;

    n = call_sv(sub, G_EVAL);

    SPAGAIN;

    if (n)
    {
        if (rv == NULL)
        {
            status = POPi;

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "call_sv: %d",
                           status);
        }
        else
        {
            line    = SvPVx(POPs, n_a);
            rv->len = n_a;

            rv->data = ngx_pnalloc(r->pool, n_a);
            if (rv->data == NULL)
            {
                return NGX_ERROR;
            }

            ngx_memcpy(rv->data, line, n_a);
        }
    }

    PUTBACK;

    FREETMPS;
    LEAVE;

    if (ctx->error)
    {
        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "call_sv: error, %d",
                       ctx->status);

        if (ctx->status != NGX_OK)
        {
            return ctx->status;
        }

        return NGX_ERROR;
    }

    /* check $@ */

    if (SvTRUE(ERRSV))
    {
        err = (u_char *)SvPV(ERRSV, len);
        while (--len && (err[len] == CR || err[len] == LF))
        { /* void */
        }

        ngx_log_error(NGX_LOG_ERR, c->log, 0, "call_sv(\"%V\") failed: \"%*s\"",
                      handler, len + 1, err);

        if (rv)
        {
            return NGX_ERROR;
        }

        ctx->redirect_uri.len = 0;

        if (ctx->header_sent)
        {
            return NGX_ERROR;
        }

        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    if (n != 1)
    {
        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                      "call_sv(\"%V\") returned %d results", handler, n);
        status = NGX_OK;
    }

    if (rv)
    {
        return NGX_OK;
    }

    return (ngx_int_t)status;
}


static void
ngx_http_perl_eval_anon_sub(pTHX_ ngx_str_t *handler, SV **sv)
{
    u_char *p;

    for (p = handler->data; *p; p++)
    {
        if (*p != ' ' && *p != '\t' && *p != CR && *p != LF)
        {
            break;
        }
    }

    if (ngx_strncmp(p, "sub ", 4) == 0 || ngx_strncmp(p, "sub{", 4) == 0
        || ngx_strncmp(p, "use ", 4) == 0)
    {
        *sv = eval_pv((char *)p, FALSE);

        /* eval_pv() does not set ERRSV on failure */

        return;
    }

    *sv = NULL;
}


static void *
ngx_http_perl_create_main_conf(ngx_conf_t *cf)
{
    ngx_http_perl_main_conf_t *pmcf;

    pmcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_perl_main_conf_t));
    if (pmcf == NULL)
    {
        return NULL;
    }

    pmcf->modules  = NGX_CONF_UNSET_PTR;
    pmcf->requires = NGX_CONF_UNSET_PTR;

    return pmcf;
}


static char *
ngx_http_perl_init_main_conf(ngx_conf_t *cf, void *conf)
{
    ngx_http_perl_main_conf_t *pmcf = conf;

    if (pmcf->perl == NULL)
    {
        if (ngx_http_perl_init_interpreter(cf, pmcf) != NGX_CONF_OK)
        {
            return NGX_CONF_ERROR;
        }
    }

    return NGX_CONF_OK;
}


#if (NGX_HAVE_PERL_MULTIPLICITY)

static void
ngx_http_perl_cleanup_perl(void *data)
{
    PerlInterpreter *perl = data;

    PERL_SET_CONTEXT(perl);
    PERL_SET_INTERP(perl);

    (void)perl_destruct(perl);

    perl_free(perl);

    if (ngx_perl_term)
    {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0, "perl term");

        PERL_SYS_TERM();
    }
}

#endif


static ngx_int_t
ngx_http_perl_preconfiguration(ngx_conf_t *cf)
{
#if (NGX_HTTP_SSI)
    ngx_int_t                 rc;
    ngx_http_ssi_main_conf_t *smcf;

    smcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_ssi_filter_module);

    rc = ngx_hash_add_key(&smcf->commands, &ngx_http_perl_ssi_command.name,
                          &ngx_http_perl_ssi_command, NGX_HASH_READONLY_KEY);

    if (rc != NGX_OK)
    {
        if (rc == NGX_BUSY)
        {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "conflicting SSI command \"%V\"",
                               &ngx_http_perl_ssi_command.name);
        }

        return NGX_ERROR;
    }
#endif

    return NGX_OK;
}


static void *
ngx_http_perl_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_perl_loc_conf_t *plcf;

    plcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_perl_loc_conf_t));
    if (plcf == NULL)
    {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     plcf->handler = { 0, NULL };
     */

    return plcf;
}


static char *
ngx_http_perl_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_http_perl_loc_conf_t *prev = parent;
    ngx_http_perl_loc_conf_t *conf = child;

    if (conf->sub == NULL)
    {
        conf->sub     = prev->sub;
        conf->handler = prev->handler;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_perl(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_perl_loc_conf_t *plcf = conf;

    ngx_str_t                 *value;
    ngx_http_core_loc_conf_t  *clcf;
    ngx_http_perl_main_conf_t *pmcf;

    value = cf->args->elts;

    if (plcf->handler.data)
    {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "duplicate perl handler \"%V\"", &value[1]);
        return NGX_CONF_ERROR;
    }

    pmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_perl_module);

    if (pmcf->perl == NULL)
    {
        if (ngx_http_perl_init_interpreter(cf, pmcf) != NGX_CONF_OK)
        {
            return NGX_CONF_ERROR;
        }
    }

    plcf->handler = value[1];

    {
        dTHXa(pmcf->perl);
        PERL_SET_CONTEXT(pmcf->perl);
        PERL_SET_INTERP(pmcf->perl);

        ngx_http_perl_eval_anon_sub(aTHX_ & value[1], &plcf->sub);

        if (plcf->sub == &PL_sv_undef)
        {
            ngx_conf_log_error(NGX_LOG_ERR, cf, 0, "eval_pv(\"%V\") failed",
                               &value[1]);
            return NGX_CONF_ERROR;
        }

        if (plcf->sub == NULL)
        {
            plcf->sub = newSVpvn((char *)value[1].data, value[1].len);
        }
    }

    clcf          = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
    clcf->handler = ngx_http_perl_handler;

    return NGX_CONF_OK;
}


static char *
ngx_http_perl_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_int_t                  index;
    ngx_str_t                 *value;
    ngx_http_variable_t       *v;
    ngx_http_perl_variable_t  *pv;
    ngx_http_perl_main_conf_t *pmcf;

    value = cf->args->elts;

    if (value[1].data[0] != '$')
    {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"",
                           &value[1]);
        return NGX_CONF_ERROR;
    }

    value[1].len--;
    value[1].data++;

    v = ngx_http_add_variable(cf, &value[1], NGX_HTTP_VAR_CHANGEABLE);
    if (v == NULL)
    {
        return NGX_CONF_ERROR;
    }

    pv = ngx_palloc(cf->pool, sizeof(ngx_http_perl_variable_t));
    if (pv == NULL)
    {
        return NGX_CONF_ERROR;
    }

    index = ngx_http_get_variable_index(cf, &value[1]);
    if (index == NGX_ERROR)
    {
        return NGX_CONF_ERROR;
    }

    pmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_perl_module);

    if (pmcf->perl == NULL)
    {
        if (ngx_http_perl_init_interpreter(cf, pmcf) != NGX_CONF_OK)
        {
            return NGX_CONF_ERROR;
        }
    }

    pv->handler = value[2];

    {
        dTHXa(pmcf->perl);
        PERL_SET_CONTEXT(pmcf->perl);
        PERL_SET_INTERP(pmcf->perl);

        ngx_http_perl_eval_anon_sub(aTHX_ & value[2], &pv->sub);

        if (pv->sub == &PL_sv_undef)
        {
            ngx_conf_log_error(NGX_LOG_ERR, cf, 0, "eval_pv(\"%V\") failed",
                               &value[2]);
            return NGX_CONF_ERROR;
        }

        if (pv->sub == NULL)
        {
            pv->sub = newSVpvn((char *)value[2].data, value[2].len);
        }
    }

    v->get_handler = ngx_http_perl_variable;
    v->data        = (uintptr_t)pv;

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_http_perl_init_worker(ngx_cycle_t *cycle)
{
    ngx_http_perl_main_conf_t *pmcf;

    pmcf = ngx_http_cycle_get_module_main_conf(cycle, ngx_http_perl_module);

    if (pmcf)
    {
        dTHXa(pmcf->perl);
        PERL_SET_CONTEXT(pmcf->perl);
        PERL_SET_INTERP(pmcf->perl);

        /* set worker's $$ */

        sv_setiv(GvSV(gv_fetchpv("$", TRUE, SVt_PV)), (I32)ngx_pid);
    }

    return NGX_OK;
}


static void
ngx_http_perl_exit(ngx_cycle_t *cycle)
{
#if (NGX_HAVE_PERL_MULTIPLICITY)

    /*
     * the master exit hook is run before global pool cleanup,
     * therefore just set flag here
     */

    ngx_perl_term = 1;

#else

    if (nginx_stash)
    {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, cycle->log, 0, "perl term");

        (void)perl_destruct(perl);

        perl_free(perl);

        PERL_SYS_TERM();
    }

#endif
}
